Mixing bass drums.

Ever wonder how come some mixes you’ve heard sound really punchy and phat? More often than not, what you’ve heard was already mastered.

But, were these great sounding bass drums the result of the mastering process alone? The answer is No. The mix itself has to have the correct bass drum level, eq and compression for this great sound to emerge.

It all starts with what you chose as your main bass drum.

Did I say the main?

Yes, you may not be even aware that the reason some bass drums sound "huge", is because of the layering of multiple kick drums (multi-layer kick drums).

The best dance remixers in the world will tell you that in order to get a big kick drum sound you need to layer two or more bass drums. There are thin kick drums that have a tremendous punch and there are heavy boomy kick drums that have a phat sound which give a tremendous presence (weight) in all bass frequencies, including the sub sonic frequencies.

Furthermore, you could have 2 different types of bass drums with similar fundamentals and sub harmonics but with two different beat patterns (i.e. one on the beat and the other off)

While these tips may not work for some of you who, for instance, record and mix classical, pop, country, blues or even rock, they are a must do for most dance, reggae, hip hop and even some R&B mixes.

Even if two bass drums have not been layered together, you usually hear a second one, for example, coming from a sample loop.

One thing remains constant in all music genres, whatever kick drum you choose for your mix, it needs to be at the correct level.

This is perhaps more important than any fancy multi-layered kick drum because if the bass drums are not leveled up enough in the mix, the purpose of multi-layering them in the first place is defeated.

Compression (See article)

It is through this processor that we can obtain control over a bass drum’s dynamics. There are no set rules of thumb to get the best sound out of a compressor, but its correct use is as important as its frequency equalization (How the kick track is equalized).

Most beginners squash the signal with the wrong amount of threshold, ratio and kill the punch by not changing the attack time. If you are not sure of what you are doing, just set the threshold so that your gain reduction is about 3 dB. Change your attack to 20ms and start with a compression ratio of 2:1.

And literally, play it by ear.

It’s better, for the most part, to leave a bass drum uncompressed with high dynamics, but at the correct level than one over-compressed at the wrong level (too low in the mix).

There are other tricks like copying the same bass drum to another track and re-arranging or filtering the frequencies between 38Hz and 200Hz so that the result is a kick track with more punch and no sub sonic information (more of this on another article :). Mixed together with the original  bass drum track, it will get the punch that is lacking. 

Equalizing.

This is where lots of you can't get it right. The reason is the control room you use for mixing and your studio monitors. Trust me, unless you are truly working in a professional studio environment, you’ll never get it perfectly right.

That doesn’t mean that you can’t help make the kick’s mix sound good enough for the ME to master it. The most frequent mistake is to submit a mix with a lame sounding kick drum and expect the mastering will “magically” make it sound like that killer-fat bass drum from the last DMX CD, or a slamming dance track from re-mixer Moby.

Forget it.

The most common mistake is to boost the lows with a generic low-frequency shelving filter and expect that the mastering engineer will make it sound bigger at his end. Again, it's not going to happen.

We (ME’s) have tricks to fix some bass drum issues, but 90% of the time these badly compressed, equalized and mixed kicks come with similar bassline problems.

The result is a mess in the low end that nobody can fix, except you of course, at your end.

Mixing kick and bassline

Now, leveling the bass drum is half the story .

Whether it’s a real fender bass guitar or a PCM (pulse code modulation) bass sample, how you layer these two will result in a well defined or undefined bass area. Working with a low cut eq filter could be the best tool to separate a kick from a bassline, but careful attention should be paid to their relative levels.

The bassline should be present but never overtaking the bass drum at any given moment throughout the mix. Also, panning the bass drum or the bassline more to one side of the stereo field is impractical because bass sounds have more weight and they sound better when they are panned dead center.

One technique often used when mixing these two elements is ducking.

Ducking

Suppose you have a bass and a drum track (both Audio not MIDI) but it seems that the kick drum sound gets "blurred" because of the bass; both have to coexist in approximately the same frequency range and the presence of the bassline tends to overwhelm the kick drum. It would then be nice if the bass was a bit softer each time the kick drum hits, right? The solution is known as "ducking" (the bass "ducks" each time the kick hits).

The picture shows the setup described above. Notice that the kick is currently playing (level meter) and the Compressor's "Gain Reduction" meter indeed shows the Compressor to be activated.

On the bass track, insert a Compressor. However, instead of letting the bass sound itself trigger the Compressor (as would normally be the case), you now pick the kick drum track from the Side Chain popup menu in the compressor. (Note that the names of the Audio Objects will not show up in the popup; you have to pick the right object by looking at the Object's parameter pane or on its channel strip, right below its Output pop-up). Additionally (important) you have to switch off "Auto Gain" in the Compressor. What you have now is a bass track that only gets compressed when the kick drum is active, thus creating a kind of "pocket" for the kick to sit inside. As for the Auto Gain: when this is on, Logic will compensate the attenuation that takes place in the Compressor, by amplifying the output signal. In this particular case you explicitly do not want that to happen: the entire idea is centered around getting the bass to play softer. Auto Gain would destroy that.

OK! Finally, try not to have your drums and bass line sub mixed, if you do or you have to, be sure to have the ability to go back to the drum mix to adjust and sub mix them back to two tracks again. Needless to say that your sub mix should be panned one track hard left and the other hard right.

Another thing, try not to mix while in real time  from a MIDI drum machine and/or other tone generators (syncing to MIDI or SMPTE) . If you do and the bass drum doesn't sound correct, you will need to adjust levels from the parameters out of those units. The draw back is that usually those MIDI devices don't have any sound reinforcement gear built-in, like compressors and equalizers. What you hear is what you get. So, transfer the sounds (separately, if possible) to a workstation and use your audio software to mix and tweak your tracks.

I have been able to re-build and re-shape bass lots of badly mixed music sources, but don’t count on this as part of the mastering process. Ultimately, it’s you and not the mastering guy who has to make sure that the sound of the bass drum(s) in your music and the overall mix is good for the mastering stage. You must be happy with the sound of your drums and bass in the first place and prior to order mastering.